Electroshock weapons - such as stun guns and other similar devices that temporarily incapacitate a person by delivering a high-voltage, low-current electric shock - have helped law enforcement officers safely subdue dangerous or violent persons for years. The use of these weapons has been challenged, however, by claims that they may have contributed to more than 150 deaths in the United States since 2001. Now, researchers at the National Institute of Standards and Technology (NIST) are working toward a standard method for accurately assessing the electrical output of these devices, the results of which can be used in establishing baselines for future medical and safety studies.

Groups such as Amnesty International have called for guidelines for electroshock weapons that include “threshold exposures” (the minimum charges that would incapacitate different groups of people without putting them at risk for injury or death). One obstacle to the development of such guidelines is the fact that various reports regarding the output of electroshock weapons—the current and voltage they deliver—are inconsistent.

To address this problem, scientists in NIST’s Office of Law Enforcement Standards (OLES) have developed methods for calibrating the high-voltage and current measurement probes used by industry so that any inherent biases in the probes are minimized. By compensating for these probe effects, voltage and current readings were obtained that reflect the energies being dispensed by the weapons.

Next steps in the characterization program for electroshock weapons include implementing a second type of high-voltage measurement to verify the probe calibration system; further refining the uncertainty analysis for the overall measurement method to better define its accuracy and reliability; and, eventually, working with government agencies and the law enforcement community to standardize the method that will facilitate establishment of use guidelines.